scholarly journals Dating the Lascaux Cave Gour Formation

Radiocarbon ◽  
2011 ◽  
Vol 53 (3) ◽  
pp. 479-500 ◽  
Author(s):  
D Genty ◽  
S Konik ◽  
H Valladas ◽  
D Blamart ◽  
J Hellstrom ◽  
...  
Keyword(s):  
Organic Matter ◽  
Eastern Mediterranean ◽  
Seepage Water ◽  
Calibration Data ◽  
Atlantic Period ◽  
Carbonate Deposit ◽  
Cave Paintings ◽  
Geomorphological Changes ◽  
Lascaux Cave ◽  
First Time

Lascaux Cave is renowned for its outstanding prehistoric paintings, strikingly well-preserved over about 18,000 yr. While stalagmites and stalactites are almost absent in the cave, there is an extensive calcite flowstone that covered a large part of the cave until its opening for tourists during the 1950s. The deposit comprises a succession of calcite rims, or “gours,” which allowed seepage water to pond in large areas in the cave. Their possible role in preservation of the cave paintings has often been evoked, but until now this deposit has not been studied in detail. Here, we present 24 new radiocarbon accelerator mass spectrometry (AMS) and 6 uranium-thorium (U-Th) analyses from the calcite of the gours, 4 AMS 14C dates from charcoals trapped in the calcite, and 4 AMS 14C analyses on organic matter extracted from the calcite. Combining the calibrated 14C ages obtained on charcoals and organic matter and U-Th ages from 14C analyses made on the carbonate, has allowed the calculation of the dead carbon proportion (dcp) of the carbonate deposits. The latter, used with the initial atmospheric 14C activities reconstructed with the new IntCal09 calibration data, allows high-resolution age estimation of the gour calcite samples and their growth rates. The carbonate deposit grew between 9530 and 6635 yr cal BP (for dcp = 10.7 ± 1.8%; 2 σ) or between 8518 and 5489 yr cal BP (for dcp = 20.5 ± 1.9%; 2 σ). This coincides with humid periods that can be related to the Atlantic period in Europe and to Sapropel 1 in the eastern Mediterranean Sea. However, geomorphological changes at the cave entrance might also have played a role in the gour development. In the 1940s, when humans entered the cave for the first time since its prehistoric occupation, the calcite gours had already been inactive for several thousand years.

Sea Surface Radiocarbon Reservoir Age Changes in the Aegean Sea from about 11,200 BP to Present

Radiocarbon ◽  
2015 ◽  
Vol 57 (3) ◽  
pp. 493-505 ◽  
Author(s):  
Yorgos Facorellis ◽  
Evi Vardala-Theodorou
Keyword(s):  
Eastern Mediterranean ◽  
Aegean Sea ◽  
Sea Surface ◽  
Archaeological Sites ◽  
Calibration Data ◽  
Marine Mollusk ◽  
Suitable Material ◽  
Paired Samples ◽  
Collection Date ◽  
First Time

Archaeological excavations in two coastal sites of Greece, Ftelia on Mykonos and Cyclops Cave on Youra, have provided suitable material (charcoal/marine mollusk shell paired samples deposited simultaneously in undisturbed anthropogenic layers) to estimate regional changes of the sea surface radiocarbon reservoir effect (ΔR) in the Aegean Sea. Moreover, pre-bomb 14C ages of marine mollusk shells of known collection date, from Piraeus and Nafplion in Greece and Smyrna in Turkey, also contributed to the marine reservoir calculation during recent years. In this article, these already published results, 10 in total, are considered and calibrated again using the latest issues of the calibration curves IntCal13 and Marine13. The same calibration data were applied to 11 more paired samples from the archaeological sites of Palamari on Skyros and Franchthi Cave in the Argolic Gulf, published here for the first time, in order to investigate the fluctuation of the reservoir ages R(t) and ΔR values in the Aegean Sea from ∼11,200 BP (∼13,000 cal BP) to present. Our data show that R(t) and ΔR values are not constant through time and may vary from 1220 ± 148 to −3 ± 53 yr and −451 ± 68 to 858 ± 154 14C yr, respectively. An attempt was also made to correlate these fluctuations with eastern Mediterranean paleo-environmental proxies and other relevant paleoceanographic data found in the literature.

scholarly journals Sicily Before the Greeks. The Interaction with Aegean and the Levant in the Pre-colonial Era

2020 ◽  
Vol 6 (1) ◽  
pp. 172-205
Author(s):  
Davide Tanasi
Keyword(s):  
Material Culture ◽  
Complex Dynamics ◽  
Eastern Mediterranean ◽  
Colonial Era ◽  
Local Material ◽  
Gradual Process ◽  
Multiple Variables ◽  
New Perspective ◽  
First Time ◽  
The Relationship

AbstractThe relationship between Sicily and the eastern Mediterranean – namely Aegean, Cyprus and the Levant – represents one of the most intriguing facets of the prehistory of the island. The frequent and periodical contact with foreign cultures were a trigger for a gradual process of socio-political evolution of the indigenous community. Such relationship, already in inception during the Neolithic and the Copper Age, grew into a cultural phenomenon ruled by complex dynamics and multiple variables that ranged from the Mid-3rd to the end of the 2nd millennium BCE. In over 1,500 years, a very large quantity of Aegean and Levantine type materials have been identified in Sicily alongside with example of unusual local material culture traditionally interpreted as resulting from external influence. To summarize all the evidence during such long period and critically address it in order to attempt historical reconstructions is a Herculean labor.Twenty years after Sebastiano Tusa embraced this challenge for the first time, this paper takes stock on two decades of new discoveries and research reassessing a vast amount of literature, mostly published in Italian and in regional journals, while also address the outcomes of new archaeometric studies. The in-depth survey offers a new perspective of general trends in this East-West relationship which conditioned the subsequent events of the Greek and Phoenician colonization of Sicily.

Middle-to late Holocene environmental changes based on a multi-proxy lagoonal record, Klisova lagoon, Greece

2021 ◽  
Author(s):  
Alexandros Emmanouilidis ◽  
Konstantinos Panagiotopoulos ◽  
Katerina Kouli ◽  
Pavlos Avramidis
Keyword(s):  
Radiocarbon Dating ◽  
Environmental Changes ◽  
Eastern Mediterranean ◽  
Anthropogenic Activities ◽  
Eastern Mediterranean Region ◽  
Anthropogenic Activity ◽  
Palynological Analysis ◽  
Drilling Site ◽  
Geomorphological Changes ◽  
Shallow Water Depth

<p>Coastal wetlands are dynamic environments prone to climatic and anthropogenic forcing and ideal settings to study past climatic and environmental changes.  In the eastern Mediterranean region and particularly in Greece, the climate presents high spatiotemporal diversity, while human activity is a significant factor in shaping the landscape. This study presents a sediment record from Klisova lagoon, situated in central Greece, at the eastern part of Messolonghi lagoon complex. The area is recorded from antiquity to have great anthropogenic activity. The paleoenvironmental synthesis was based on standard sedimentological analysis (grain size, TOC, magnetic susceptibility), joint micropaleontological and palynological analysis, X-ray Fluorescence scanning, and radiocarbon dating. The Bayesian age-depth model is based on radiocarbon dating and yields an age of 4700 cal BP for the base of the recovered sediment sequence. For the last 4700 years, the freshwater influx, the progradation of the Evinos river delta and related geomorphological changes control the environmental conditions (e.g. depth and salinity) in the lagoon system. Prior to 4000 cal BP, a relatively shallow water depth, significant terrestrial/freshwater input and increased weathering in the lagoon area are inferred. Elemental proxies and increased dinoflagellate and foraminifera abundances, which indicate marine conditions with prominent freshwater influxes, point to the gradual deepening of the lagoon recorded at the drilling site up to 2000 cal BP. The marine and freshwater conditions equilibrium sets at 1300 cal BP, and the lagoonal system seems to reach its present state. Maxima of anthropogenic pollen indicators during the Mycenaean (~3200 cal BP), Hellenistic (~ 2200 cal BP) and Late Byzantine (~ 800 cal BP) periods suggest intervals of increased anthropogenic activities in the study area.  </p>

scholarly journals Species of Geotrupidae (Coleoptera: Scarabaeoidea) in Aquidauana, Mato Grosso do Sul, Brazil

2013 ◽  
Vol 13 (1) ◽  
pp. 349-352
Author(s):  
Sérgio Roberto Rodrigues ◽  
Anderson Puker
Keyword(s):  
Organic Matter ◽  
Light Trap ◽  
Abundant Species ◽  
Ecological Role ◽  
Mato Grosso ◽  
The Family ◽  
Total Capture ◽  
First Time ◽  
Mato Grosso Do Sul

Coleoptera of the family Geotrupidae play an important ecological role in the decomposition of animal and plant organic matter. In Brazil there is little information on the diversity and distribution of this group, thus, this work had a purpose to study Geotrupidae species, occurring in Aquidauana, MS. A survey for geotrupids was conducted in Aquidauana, Mato Grosso do Sul, Brazil. Beetles were captured using a light trap over a period of two years, from January 2006 to December 2007. A total of 907 specimens were collected and identified to eight species. From the subfamily Bolboceratinae, the species identified were Bolbapium minutum (Luederwaldt, 1929) and Pereirabolbus castaneus (Klug, 1845). In the subfamily Athyreinae the species identified were Athyreus bilobus Howden & Martínez, 1978, Parathyreus aff. bahiae, Neoathyreus aff. julietae, N. sexdentatus Laporte, 1840, N. centromaculatus (Felsche, 1909) and N. goyasensis (Boucomont, 1902). Four species (A. bilobus, N. centromaculatus, N. goyasensis and P. castaneus) are reported for the first time in Aquidauana, MS, Brazil. The most abundant species, representing 85.9% of the total capture, was B. minutum. The greatest numbers of specimens was caught from October to December of both years of the study.

scholarly journals Temperature and UV light affect the activity of marine cell-free enzymes

2017 ◽  
Vol 14 (17) ◽  
pp. 3971-3977 ◽  
Author(s):  
Blair Thomson ◽  
Christopher David Hepburn ◽  
Miles Lamare ◽  
Federico Baltar
Keyword(s):  
Organic Matter ◽  
Extracellular Enzymes ◽  
Elevated Temperatures ◽  
Uv Light ◽  
Control Mechanisms ◽  
Potential Control ◽  
Control Factors ◽  
Rate Limiting Step ◽  
Ocean Environment ◽  
First Time

Abstract. Microbial extracellular enzymatic activity (EEA) is the rate-limiting step in the degradation of organic matter in the oceans. These extracellular enzymes exist in two forms: cell-bound, which are attached to the microbial cell wall, and cell-free, which are completely free of the cell. Contrary to previous understanding, cell-free extracellular enzymes make up a substantial proportion of the total marine EEA. Little is known about these abundant cell-free enzymes, including what factors control their activity once they are away from their sites (cells). Experiments were run to assess how cell-free enzymes (excluding microbes) respond to ultraviolet radiation (UVR) and temperature manipulations, previously suggested as potential control factors for these enzymes. The experiments were done with New Zealand coastal waters and the enzymes studied were alkaline phosphatase (APase), β-glucosidase, (BGase), and leucine aminopeptidase (LAPase). Environmentally relevant UVR (i.e. in situ UVR levels measured at our site) reduced cell-free enzyme activities by up to 87 % when compared to controls, likely a consequence of photodegradation. This effect of UVR on cell-free enzymes differed depending on the UVR fraction. Ambient levels of UV radiation were shown to reduce the activity of cell-free enzymes for the first time. Elevated temperatures (15 °C) increased the activity of cell-free enzymes by up to 53 % when compared to controls (10 °C), likely by enhancing the catalytic activity of the enzymes. Our results suggest the importance of both UVR and temperature as control mechanisms for cell-free enzymes. Given the projected warming ocean environment and the variable UVR light regime, it is possible that there could be major changes in the cell-free EEA and in the enzymes contribution to organic matter remineralization in the future.

scholarly journals Source rock characterization of mesozoic to cenozoic organic matter rich marls and shales of the Eratosthenes Seamount, Eastern Mediterranean Sea

2018 ◽  
Vol 73 ◽  
pp. 49 ◽  
Author(s):  
Sebastian Grohmann ◽  
Susanne W. Fietz ◽  
Ralf Littke ◽  
Samer Bou Daher ◽  
Maria Fernanda Romero-Sarmiento ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mediterranean Sea ◽  
Source Rock ◽  
Eastern Mediterranean ◽  
Source Rocks ◽  
Eastern Mediterranean Sea ◽  
Potential Source Rock ◽  
Levant Basin ◽  
Rock Characterization ◽  
Rock Eval

Several significant hydrocarbon accumulations were discovered over the past decade in the Levant Basin, Eastern Mediterranean Sea. Onshore studies have investigated potential source rock intervals to the east and south of the Levant Basin, whereas its offshore western margin is still relatively underexplored. Only a few cores were recovered from four boreholes offshore southern Cyprus by the Ocean Drilling Program (ODP) during the drilling campaign Leg 160 in 1995. These wells transect the Eratosthenes Seamount, a drowned bathymetric high, and recovered a thick sequence of both pre- and post-Messinian sedimentary rocks, containing mainly marine marls and shales. In this study, 122 core samples of Late Cretaceous to Messinian age were analyzed in order to identify organic-matter-rich intervals and to determine their depositional environment as well as their source rock potential and thermal maturity. Both Total Organic and Inorganic Carbon (TOC, TIC) analyses as well as Rock-Eval pyrolysis were firstly performed for the complete set of samples whereas Total Sulfur (TS) analysis was only carried out on samples containing significant amount of organic matter (>0.3 wt.% TOC). Based on the Rock-Eval results, eight samples were selected for organic petrographic investigations and twelve samples for analysis of major aliphatic hydrocarbon compounds. The organic content is highly variable in the analyzed samples (0–9.3 wt.%). TS/TOC as well as several biomarker ratios (e.g. Pr/Ph < 2) indicate a deposition under dysoxic conditions for the organic matter-rich sections, which were probably reached during sporadically active upwelling periods. Results prove potential oil prone Type II kerogen source rock intervals of fair to very good quality being present in Turonian to Coniacian (average: TOC = 0.93 wt.%, HI = 319 mg HC/g TOC) and in Bartonian to Priabonian (average: TOC = 4.8 wt.%, HI = 469 mg HC/g TOC) intervals. A precise determination of the actual source rock thickness is prevented by low core recovery rates for the respective intervals. All analyzed samples are immature to early mature. However, the presence of deeper buried, thermally mature source rocks and hydrocarbon migration is indicated by the observation of solid bitumen impregnation in one Upper Cretaceous and in one Lower Eocene sample.

scholarly journals Αλλαγές στις θαλάσσιες βακτηριακές κοινότητες σε συνθήκες εμπλουτισμού με θρεπτικά

2014 ◽  
Author(s):  
Στυλιανός Φοδελιανάκης
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Nutrient Enrichment ◽  
Eastern Mediterranean ◽  
Community Diversity ◽  
Coastal Sediment ◽  
Common Source ◽  
Composition And Structure ◽  
Taxonomic Groups ◽  
Bacterioplankton Communities

Nutrient enrichment is a common source of disturbance for marineecosystems. A prerequisite for the prediction of the effects of nutrient enrichment atthe ecosystem level is the understanding of the ecological mechanisms governingbacterioplankton communities, due to their high affinity with nutrients. The aim ofthis thesis was to examine changes in the composition and structure ofbacterioplankton communities of the water column and coastal sediment undernutrient enrichment. Three studies were conducted for that purpose: two in closedexperimental conditions and one examining changes in situ. In the first two studies,changes in the water column bacterioplankton communities were examined after Paddition and in nutrient enriched habitats, respectively. In the third study, changes inthe communities of coastal sediment were examined with and without the additionof organic matter and aeration of the water column. The main conclusions from theresults of this thesis were:a) Bacterioplankton communities of the Eastern Mediterranean show a high degreeof resistance to short-term P addition, although their biomass and production islimited by P.b) Five abundant taxonomic groups showed a similar pattern of change across threedifferent nutrient enriched habitats. These groups could be potentially used asindicators for monitoring nutrient enrichment at the water column.c) After incubation under presence or absence of organic enrichment, sedimentbacterial communities originating from different habitats clustered based on theincubation conditions rather than on the area of origin. That occurred faster for twoout of the three areas, where the amount of organic matter in the sediment wasinitially higher and bacterial community diversity was lower. These results indirectlysupport the theory of Baas-Becking that "everything is everywhere but theenvironment selects" and the positive correlation between diversity and communitystability.

scholarly journals Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

2010 ◽  
Vol 7 (1) ◽  
pp. 1131-1165 ◽  
Author(s):  
J. Möbius ◽  
N. Lahajnar ◽  
K.-C. Emeis
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Surface Sediments ◽  
Eastern Mediterranean ◽  
Nitrogen Isotope ◽  
Organic C ◽  
Deep Waters ◽  
Spatially Distributed ◽  
Temporal And Spatial ◽  
Recent Sediments

Abstract. The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually depleted δ15N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and δ15N on sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10-6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in δ15N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) that present day TOC export production would suffice to create a sapropel like S1 under conditions of deep-water anoxia. This implies that both enhanced TOC accumulation and δ15N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt the need of enhanced primary production for sapropel formation.

scholarly journals On the genesis of aluminum-rich speleothems in a granite cave of NW Spain

2021 ◽  
Vol 50 (1) ◽  
pp. 25-40
Author(s):  
Jorge Sanjurjo-Sanchez ◽  
◽  
Carlos Arce Chamorro ◽  
Juan Vidal Romaní ◽  
Marcos Vaqueiro-Rodríguez ◽  
...  
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Growth Process ◽  
Age And Growth ◽  
Nw Spain ◽  
Geochemical Composition ◽  
Cave System ◽  
Accretion Process ◽  
Dissolved Ions ◽  
First Time

Granite massifs often contain caves, with dimensions ranging from a few meters up to 1,000 m, also referred to as pseudokarst. The speleothems in such caves are mostly composed of either Si-rich (commonly opal-A) or Al-rich authigenic mineraloids. Whereas the formation and geochemical composition of opal-A biospeleothems have been studied and are fairly well understood, knowledge on the Al-rich analogues is scarce. This work reports for the first time a study on the composition, accretion process, age and growth rate of an Al-rich speleothem type flowstone from the A Trapa Cave System (Galicia, NW Spain), developed in a granite cave. To understand the growth process, trickling water was analyzed and the deposition environment inside the cave was characterized. We found that the speleothems are alternating Si- and Al-rich layered deposits formed between 1,635 ± 75 and 1,243 ± 58 cal BP by percolating water that carries underground mineral grains, dissolved ions, and organic matter from soil and the weathered bedrock above the cave.

scholarly journals First record of the blackfish Centrolophus Niger (Teleostei: Centrolophidae) from the Lebanese waters in the eastern Mediterranean sea

2020 ◽  
Vol 21 (2) ◽  
pp. 240-243
Author(s):  
Ali badreddine ◽  
◽  
Ghazi Bitar ◽  
Keyword(s):  
Mediterranean Sea ◽  
Present Note ◽  
Eastern Mediterranean ◽  
First Record ◽  
Eastern Mediterranean Sea ◽  
Young Specimen ◽  
First Time

A young specimen of the blackfish, Centrolophus niger (Gmelin, 1789) was reported for the first time from the Lebanese waters. It was caught and photographed by a professional fisherman in Beirut, on 15th November 2014. The present note reports details about this first record.

Sign in / Sign up

Export Citation Format

Share Document